出典:Wiktionary
From earlier hem, from Middle English hem, from 古期英語 heom (“them”, dative) of hie,[1] originally a dative plural form but in Middle English coming to serve as an accusative plural as well. Cognate with Dutch hun (“them”), German ihnen (“them”).
Now often treated as a form of them, which however derives from Old Norse rather than 古期英語.
'em
em-